Vehicle Power Management via Segmented Battery Architecture
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Solution Overview
Problem
Hybrid electric vehicles face challenges in efficiently managing electric power distribution between batteries and loads, particularly during engine start-stop cycles and regenerative braking, leading to inefficiencies in fuel consumption and voltage stabilization.
Innovation Solution
An electric power management system with a controller that monitors battery states of charge and selectively couples power buses to optimize energy flow, using switches to route power between a first and second node, ensuring efficient power distribution and stabilization across various vehicle operating modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a single battery system is used in traditional vehicles, then the system structure is simple, but the fuel consumption increases and energy efficiency decreases during engine start-stop cycles
Solution Approach 1:
The power management system is segmented into two separate batteries: a first battery (12V) for auxiliary loads and a second battery (48V) for engine starting and energy storage. This segmentation allows independent optimization of each battery's function, enabling the second battery to capture regenerative braking energy and provide start-stop power without affecting the first battery's stability for auxiliary loads, thereby reducing overall energy loss while maintaining manageable system complexity through modular architecture
Solution Approach 2:
A controller acts as an intermediary between the two batteries and the power buses, intelligently managing power flow distribution. The controller monitors states of charge and operating conditions, selectively activating switches to route power from either battery or both batteries to different loads. This intermediary control enables optimized energy management that reduces fuel consumption during start-stop cycles while preventing system complexity from becoming unmanageable
2Productivity
If multiple power buses are used to manage power distribution between batteries and loads, then the power distribution efficiency improves, but the voltage stabilization becomes challenging during engine start-stop events
Solution Approach 1:
The electrical system is divided into separate power buses: a first power bus for the 12V battery and auxiliary loads, and a second power bus for the 48V battery and engine starter. This segmentation isolates voltage fluctuations during engine starting on the second bus from the first bus, maintaining voltage stability for auxiliary loads while allowing efficient power distribution through dedicated buses for each function
Solution Approach 2:
The controller serves as an intermediary that actively manages voltage stability across multiple power buses by monitoring states of charge and selectively activating switches. During engine start-stop events, the controller coordinates power delivery from the second battery through the second power bus while preventing voltage transients from affecting the first power bus, thus maintaining overall system voltage stability despite the complexity of multiple buses
3Loss of energy
If the generator operates as a motor to restart the engine after autostop, then the regenerative braking capability is improved, but the power management complexity increases during engine start-stop cycles
Solution Approach 1:
The generator is designed with multi-functionality, operating as a generator during normal engine operation to produce electrical power, as a motor during engine start-stop cycles to restart the engine, and as a generator during regenerative braking to capture kinetic energy. The controller manages these different operating modes by monitoring system state and selectively activating appropriate power flow paths, enabling the generator to perform multiple functions without requiring separate dedicated motors, thus improving regenerative braking efficiency while keeping power management complexity manageable through intelligent control
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system enables efficient energy management, reducing fuel consumption, maintaining a stabilized low-voltage electrical power supply, and preventing lamp flicker during engine autostart events, while allowing for coasting energy recuperation and opportunity charging.
Implementation Method 1
a generator (40) that is mechanically coupled to the engine (20) and that is selectively operable in a generator mode to generate electrical energy in response to rotation by the engine (20)
Implementation Method 2
a starter motor (30) selectively operable in a motor mode to provide mechanical energy in response to activation, to rotate the engine (20) and start the engine (20)
Data Source
AI summary
An electric power management system for a vehicle includes a first power bus arranged in parallel with a second power bus between first and second nodes. A third power bus couples a first battery and an auxiliary load at the second node. The second power bus couples a starter, a second battery and a generator at the first node, and selectively couples the first node to the second node when a first switch is activated. The second battery couples to the first node when a second switch is activated and the engine starter couples to the first node when a starter switch is activated. The second power bus couples the first node to the second node when a third switch is activated. A controller monitors states of charge of the first battery and the second battery and controls activations of the first switch, the second switch and the third switch.